The Why Files The Why Files --

Studying the invisible

POSTED 10 FEB 2005
When quantity equals quality
Sticks and stones can break your bones, but neutrinos will never hurt you...One of the big advantages of the Fermilab neutrino project is quantity: it is expected to detect about 1,500 neutrinos per year, at a cost of $171-million for equipment, excavation, and installation. That figure does not include salaries for more than 200 researchers from Brazil, France, Greece, Russia, the United Kingdom and the United States. The project was funded by the U.S. Department of Energy, the National Science Foundation, the British Particle Physics and Astronomy Research Council, the State of Minnesota and the University of Minnesota.

When you spend that kind of money, you worry about a lot of stuff. One thing you don't have to fret about is health damage from neutrinos -- whether "natural" neuts from the sun, or unnatural neuts, like those Fermilab is making: Sticks and stones can break your bones, but neutrinos will never hit you... And that's a good thing, as we are drenched in a constant rain of neutrinos.

 Huge steel plates surrounded by walkways, computers, wires and concrete.
A 980-ton rack of steel plates (blue) detects neutrinos at Fermilab's near detector.

Making meaning
So you've reached this point, but you still can't see the point of neutrino research. Why worry about a particle so light that it costs a couple hundred million bucks to measure its mass? Well, one massless particle is called the photon, and it carries light...

While light is handy for practical and scientific purposes, neutrinos are a key to understanding the world on the smallest scale. Nobody's promising anything practical like, say, a neutrino-based computer memory or neutrino treatment for disease.

Instead, the goal is simple: to learn more about a particle that hates to be measured. "The goal is to nail down the parameters of neutrino oscillation, measure the properties," Greg Bock, project manager for neutrinos source, tells us at lunch. Bock says that after one year of operation, the researchers hope to amass enough data to make an initial estimate of how fast neutrinos change flavor.

Neutrino science could help remodel the standard model of physics.

The Why Files asked Edward Kearns, a neutrino researcher at Boston University, about the significance of neutrinos. "The first answer is that it's basic research, and that has a long history in the United States and elsewhere. If you pursue basic research, not only are you showing that there is intellectual vigor in your society, but you find all sort of things that have unexpected consequences, and that may have a payback."

Such a statement is particularly relevant to users of the web, says Kearns: "The world wide web was developed by particle physicists to talk to each other at CERN," the European particle physics lab. Other important technologies have roots in particle physics, he adds. "Medical imaging often has very close ties to particle physics, and the original proton therapies for cancer were done at labs like Fermilab, so there are definitely spin-offs."

The 6,000-ton far detector in Soudan, Minn., contains hundreds of steel plates.
The 6,000-ton far detector in Soudan, Minn., contains hundreds of steel plates. Photo: Fermilab

The root of the interest in neutrinos is this: particle physicists want "to boil things down to small number of rules," Kearns says. "If there are any loose ends, we have to take that string and pull on it. We never knew if neutrinos had mass, but mass made them interfere with each other [causing a change in flavor]. ... This is telling us something fundamental about the neutrino, but we have not figured out what to do with the information.

Bet you can figure out what to do with information in our bibliography...


Megan Anderson, project assistant; Terry Devitt, editor; S.V. Medaris, designer/illustrator; David Tenenbaum, feature writer; Amy Toburen, content development executive

©2021, University of Wisconsin, Board of Regents.